PLELOTAXY. 371 
Coniferze, which he considers to be improperly termed 
polycotyledonous. Whether this holds good in the 
Loranths, where (Nuytsia, Psittacanthus) an appearance 
of polycotyledony exists, is not stated. In the case of 
the rue (Ruta) figured by M. A. de Jussieu’ this 
splitting of one cotyledon into two is sufficiently evi- 
dent, as is also the case in the sycamore (Acer pseudo- 
platanus), seedlings of which may often be met with 
divided cotyledons. 
In other instances a fusion of two embryo plants 
may give rise to a similar appearance, as in the 
Euphorbia and Sinapis found by M. Alph. de Candolle 
(see ante, p. 56). 
Pleiotaxy or multiplication of whorls—In the preceding 
section notice has been taken of the increased number 
of parts in a single whorl, but an augmentation of the 
number of distinct whorls is still more frequently met 
with. Many of the so-called double flowers owe their 
peculiarity to this condition. The distinction between 
the two modes in which the parts of the flower are 
increased in number has been pointed out by Engel- 
mann, Moquin, and others, and the two seem to require 
distinctive epithets ; hence the application of the terms 
polyphylly and pleiotaxy, as here proposed. 
Pleiotaxy in the bracts—An increase in the number of 
bracts has been met with very constantly in a species 
of Mesa, and in a peculiar variety of carnation, called 
the wheat-ear carnation.” In some of these cases the 
increase in the number of bracts is attended by a cor- 
responding suppression in the other parts of the flower. 
Such a condition has been frequently met with in 
Gentiana Amarella, where the bracts are increased in 
1 ¢Mem. Mus.,’ xii, t. 17. 
2 ‘Nov. Act. Acad. Nat. Cur.,’ xv, tab, xxviii, f.3; ‘ Bot. Mag.,’ t. 1622. 
“Caryophyllus spicam frumenti referens.” A similar malformation in 
Dianthus barbatus is not uncommon. It has lately been introduced into 
gardens under the name of Dianthus “mousseuzx,” but is not likely to 
find favour with gardeners. 
